Near-Future Strengthening of ENSO-Related Sea Ice Variability in We st Antarctica

Abstract

The increasing interannual variability of Antarctic sea ice near West Antarctica underscores the need to understand how El Niño–Southern Oscillation (ENSO) teleconnections may shape future sea ice changes. Using simulations from the Coupled Model Intercomparison Project Phase 6, this study investigates the projected impacts of near-future ENSO variability on Antarctic sea ice. ENSO teleconnections are found to primarily influence Antarctic sea ice from austral winter through spring, and this influence is projected to strengthen in the near future. We show that the strengthened teleconnection is driven mainly by enhanced tropical forcing with the structural changes in tropical sea surface temperatures and precipitation, with a smaller contribution from changes in the midlatitude jet waveguide. These mechanisms are further supported by idealized nudging experiment using a dry dynamic core model. The strengthened teleconnection deepens the ENSO-induced mid-tropospheric circulation anomaly near West Antarctica, enhancing warm-air advection and the resulting sea ice anomalies. Overall, these changes are projected to increase Antarctic sea ice variability in the near future, highlighting the importance of understanding how evolving ENSO teleconnections may modulate Antarctic climate variability.